The purpose of this survey was to make an initial sociolinguistic documentation of Kua-nsi (夸恩斯话) and related Yi (Ngwi) varieties of northern Heqing county (鹤庆县), Yunnan province, and to make a preliminary evaluation of levels of inter-comprehension and lexical similarity. Five different language varieties were documented: Kua-nsi (夸恩斯话), Kuamasi (夸玛斯话), Laizisi (莱兹斯话), Zibusi (子逋斯话) and Sonaga (锁内嘎话). Based on an initial evaluation, the authors believe that none of these varieties are mutually intelligible to a high degree. Based on both lexical similarity scores and Levenshtein distance analysis, the closest known Yi variety to Kua-nsi is Talu (他留话), spoken in Yongsheng county (永胜县). All of the varieties examined exhibit typical features of other Central Ngwi languages, such as Lalo (拉罗话) and Lolo (倮倮话). They are all threatened speech varieties. Kua-nsi, with over 5,000 speakers, and Sonaga, with over 2,000 speakers, can be said to have the highest linguistic and cultural vitality.